Many of them are patchable, but I'm running tubeless now, so I don't really have the need for them. Plus, they're all 26" tubes. I figured Yellow Bike could easily patch them and give them out as spares, but they already had what they needed.
Also, I just got off the phone with REI and they were willing to take all the tubes (and the tires too), but they currently can't take them because the recycling company has temporarily stopped picking up the rubber.
These things have been in my garage for a while now, so a little while longer won't hurt. In the meantime I can start making them into slingshots.